Are there standard patterns for vertical radio-button like choices in tables?

Question

In my application, I have a table of entities - in this case, the individual offices of a member organization. One entity - one office - has to be marked as the 'main' office, or headquarters.

It would be simplest if the user could set a main office within the table, rather than open each office's details form. A user needs to decide between several offices, so it makes sense that she be able to see all of them (and their details) when she makes her choice. I need a way for users to mark one entry in the table as the 'preferred' choice, then.

However, I'm unaware of any common patterns that do this. I have seen radio buttons in vertical formation, but not in tables (most radio buttons in tables are part of a horizontal series). Is there any common and intuitive pattern for selecting a single entry in a table?

The only design I can think of is an 'empty' column with the header 'HQ'. If the user clicks a cell, that row is chosen, and the cell takes either the text 'HQ' or a symbol that's suitable in the domain (perhaps a building symbol). Are there any better choices?

Also, on a more general note, are vertical 'radio button'-like selections a good idea in the first place? Or do users prefer to choose from a horizontal selection?

Answer 1

Rather than an "empty" column that can be clicked, add a column with a radio button (1 per row). One of the conventions I think looks best and find easiest to read/use is having the cell with the radio button be on the end of the table row (either far left or far right cell), and have no border on the cell (as though the button were next to the table rather than in it, but the appeal of this option depends on the layout and style/design of the table/surrounding area, and may look better the other way).

I do, however, like your idea of adding "HQ" or an appropriate image. If possible (I don't know what platform/language you are doing this in), you could mix the two, and have radio buttons that become such an element when selected (and change back when deselected).